An aircraft, such as a helicopter, has many critical components that are required to operate properly in order to achieve flight safety. In the past, monitoring of these critical components was performed through manual inspection, for example, before and after flights. These manual inspections, however, were inefficient and in many cases, insufficient to predict a critical component failure. To overcome some of the limitations of manual inspections, Health and Usage Monitoring Systems (HUMS) have been installed on many aircraft. The use of HUMS have not only resulted in improvements in aircraft safety but have also increased operational readiness of entire aircraft fleets by enabling operators to proactively identify and correct defects as well as minimize unscheduled maintenance and logistics cost.
A typical HUMS includes numerous sensors, such as accelerometers, that are placed on critical components of an aircraft such as the aircraft's engine and drive system. The sensors gather data relating to parameters of the monitored components and provide the data to one or more on-board data acquisition units. The data is then transferred from the data acquisition units to a ground station and other computer systems for operator analysis. As an example, if a helicopter experiences a relatively high tail rotor drive shaft torque loading over a certain period of time, vibratory irregularities or deflection anomalies, the HUMS acquires the relevant data from the sensors for operator analysis such that timely inspection and/or maintenance of bearings or other aircraft systems can be performed. While HUMS have greatly improved the overall safety records of aircraft employing this technology, it has been found that due to the significant volume of data gathered and processed by HUMS for aircraft fleets, important data relating to specific aircraft components of a particular aircraft within a fleet may sometimes be missed or overlooked by operators.